Missing
by NerdofSpades
Summary: Izuku lost his notebook. It wasn't that big of a deal, could be worse, but it was still missing and he needed to find it. It just so happens that finding it now involves getting help from the rest of the class... and his teachers.


**Just a not so little fic I've been sitting on for a little while. It's set somewhere between when Izuku and Bakugou get off house arrest and the start of internships.**

 **I was originally going to try and do a more detailed and longer multi-chapter fic outlining what would happen if a villain _did_ get their hands on one of Izuku's notebooks, but that just wasn't in the cards, so you guys get this instead. I know a lot of other people have done fics like this before but... *shrugs* it's the two cakes principle.**

 **There's one last little note at the bottom to clarify a term I used (and provide credit where it's due).**

* * *

Midoriya huffed to himself as he shuffled around his room. It was time to try something else, considering he had already searched his dorm room top to bottom at least four times. He stood and walked down to the common room on the main floor.

"Hey, guys," Midoriya greeted as he walked in, not even checking exactly who was in the room, just that there were people, "have any of you seen my notebook?"

"Nope," Ashido replied, tipping her head back over the couch to look at him upside down.

"What class is it for?" Yaoyorozu asked.

Midoriya shook his head. "It was my quirk journal."

"You keep a journal about your quirk?" Sato asked, looking surprised. "Like for training or something?"

"Nah, man," Kirishima answered quickly. "He's got these super manly journals where he analyses quirks and comes up with strategies. Are you okay, Bakugou?"

Bakugou had gone still, his anger radiating out in waves, a thunder cloud of emotion forming over him. Kirishima's voice jolted him back into motion, rising to his feet and stalking over to Midoriya. A snarl pulled at his lips and his shoulders tensed along with his hands as he restrained the explosions he desperately wanted to let loose to make the damned nerd and everyone else understand just how bad this was. "You _lost_ one of your journals?" he asked, his voice a low growl rising over the tense silence.

Midoriya nodded.

"And you're not concerned?"

"It could be worse," Midoriya shrugged. "It's not like I lost number thirteen."

Bakugou released a sudden burst of explosions, the crackles causing the group of observers to flinch and smoke to curl between his fingers, tickling Midoriya's nose. "And all your analysis on us, our teachers, and whatever random pro you see isn't dangerous? That thing was full."

"Oh," Midoriya's eyes went wide. "No, no, no, not number fourteen, number fifteen. I just started it today with Uraraka and Iida when we went out. I was showing them how I analyze quirks because they wanted to try their hand and wanted something to start with."

"So you lost detailed analysis of random pros. How many did you do?" He seemed slightly more relaxed, but the others were getting more worried as they began to understand why the explosive boy had reacted so badly.

Midoriya thought for a moment. "We ran across three fights, so… ten heroes and four villains. And most of the fights were fairly short, so I didn't get much. I didn't write any names."

"It's still enough to be dangerous."

"I mean, yeah, but, again, it could be _a lot_ worse, and I know I brought it back to the dorms!"

"Hey, uh, quick question?" Ashido interrupted. "I get why we should be very worried about Mido missing a journal, but what's so bad about number thirteen?"

Midoriya winced. "I wrote some things I really shouldn't have. A large portion of it has been rendered harmless at this point, but it's still got some other stuff, and if people realize _when_ it was written… that would be bad." Very bad. Placed under house arrest until he somehow managed to graduate bad. If not hunted down and held hostage bad.

"You wrote down _that_!" Bakugou's disbelieving cry was punctuated by more explosions. "That's it, I'm burning all of them!"

"Wait!" Midoriya cried darting after the angry blond. "At least let me save two pages!"

Ashido's eyes glinted. "What did you write, Mido!?" she yelled, vaulting over the couch to chase after them. "And what's on those two pages!?"

Before they could reach the stairs, thin, grey fabric lashed out, wrapping around all three of them and binding Bakugou and Midoriya together.

On the other side of the room stood the exhausted and clearly annoyed homeroom teacher. He had come to check in on the class and do a quick inspection (after a surprise drill) and instead he finds Bakugou threatening to destroy a classmate's property, Midoriya not even trying to stop him, and the rest of the students present looking vaguely concerned and a little sick to varying degrees.

"What," he drawled slowly, releasing his quirk and recalling his capture weapon when he was sure his students wouldn't run off, "is going on here?"

At first, no one answered, waiting for someone else to handle it. Bakugou's patience ran out first.

"Deku lost his fucking quirk analysis notebook," he snapped.

"And why does that mean you get to burn Midoriya's stuff?"

Midoriya looked sheepish.

"Because we're in the others, among other things."

"Most of the class is only in thirteen and fourteen. But Kacchan… yeah, he's in all of them. And, uh, the whole burning thing is understandable. I just want to save two pages."

Aizawa's cold gaze shifts to the problem child. "And you just carry these notebooks with you?"

"No!" Midoriya squawked. "I mean, not anymore! And I've always been careful with them. This is the first time since I was five that I can't say where one is, but I know I brought it back to the dorms, so I know it's here somewhere." By the end, Midoriya's words were a jumbled, half muttered mess.

"But what's on those pages!?" Ashido whined.

Aizawa raised an eyebrow, gaze still firmly on Midoriya.

Midoriya blushed bright red, eyes turning to the floor as he mumbled under his breath. Bakugou, who was the only person close enough to hear, blinked in surprise, then nodded in understanding.

"Louder, Midoriya," Aizawa ordered.

Midoriya swallowed and shuffled nervously. "I, uh, I said it was All Might's signature."

"You can always-"

"Get another, I know." Midoriya seemed to be getting his wits back. "This one is special to me. It's from the first time I met him."

"I don't remember you asking his for an autograph in class," Kirishima interrupted, a small frown on his usually smiling face.

Midoriya went red again. "No, we, uh, we met before school started."

Aizawa had known this since the first day when he caught All Might spying (trying to, anyway) nervously on his quirk test and mentioned Midoriya's potential. He wasn't surprised when none of his students reacted either. All Might had never been able to hide his fondness for the boy. In fact, the two were so obvious he'd be worried for anyone who was surprised.

"Midoriya, go get your notebooks. Everyone else is going to look everywhere to try and find the missing one." The kids leapt into action. No hesitation, that was good. "Midoriya," the boy stopped at the foot of the stairs. "You were out with Uraraka and Iida, right?"

Midoriya nodded,

"They'll go out with Midnight and Present Mic to retrace your steps. Now, go get your books."

It didn't take long for all of 1-A to get worked up into a bit of an uproar. By the time Midoriya rounded up all fourteen remaining journals, the living room looked like a disaster area, and Uraraka and Iida had left with their pro hero escort. Aizawa took one look at the stack, grabbed the top half, and left with Midoriya quickly following.

When the pair made it to the offices (which were empty, it was an off day) Aizawa casually told Midoriya to show him the signature. He spared only a moment to snort at the large scrawl across the two-page spread before carefully removing the pages, covering the backs with a thick white paint that completely hid the notes, and then laminated it and returned them.

Then he sat, directed Midoriya to a chair and grabbed number fourteen and read.

The silence stretched on, turning pages and nervous fidgeting the only sounds.

Finally, Aizawa closed the book and turned his gaze back to his student. "I didn't see anything about me."

"You're mostly in thirteen, a little in the earlier ones. I don't usually get new information on you unless things, uh, go _really_ wrong," Midoriya said, even as Aizawa picked up the next journal and started flipping through, much faster this time, only taking a cursory glance and pausing from time to time when he found something interesting. One point in particular he stopped entirely to give his student a very flat look that managed to convey disappointment. Maybe a little surprise, but mostly disappointment that his student was stupid enough to write this down. He knew Midoriya knew which notes he'd seen, and that he'd been expecting it by how his fidgeting came to a sudden stop and he gazed confidently back. Then, after making a mental note to sit Midoriya and Yagi down to talk about _that_ later, he went back to reading. When he was done he snapped the book shut, placed it on the table, and stood, striding across the room and locking the door.

"U-um… S-sir?" Midoriya asked, swallowing the lump in his throat.

Aizawa forced himself not to sigh, slump his shoulders, bang his head against the wall, or otherwise show his frustration. Because, seriously? He was used to strange situations and students that either simply didn't listen or that threw themselves into danger too quickly, but he'd never had one cause as many problems as Midoriya did. "Midoriya," he started as he reclaimed his seat, "do you understand why these notebooks are so dangerous?"

"I mean, yeah," Midoriya squirmed again. "I write down some stuff that other people don't think of or don't get a chance to observe, especially after I started at UA. But it's not like there's much else, and I've always kept a close eye on them. I was going to let Kacchan burn them because he's the most at risk." Aizawa raised an eyebrow. "Other than maybe me and All Might," he quickly amended.

That wasn't what he was looking for, but it was something. "I'm going to come back to your self-image problems in a moment," he said first. "What do you count as 'keeping an eye on them'?"

Midoriya sat a little straighter. "I kept the one I was working on close to me. Usually in my bag or my hands. The old ones were kept in my room, and I checked to make sure they were still there every night."

"From the very start?" Aizawa interrupted.

"N-no. Since I was…" he paused, "eight? Yeah, I think I was eight. No one would've noticed me until UA anyway."

Aizawa nodded and gestured for Midoriya to continue. The boy thought for a moment. "After I started at UA, I began keeping the current one in the lockers. Other than that…" he shrugged. "Not much to do. They're safe enough."

Aizawa snorted. "Normally, I'd agree with you," he said. He leveled a firm look at Midoriya. "What I'm about to tell you, does not leave this room, Problem Child. You don't tell anyone, and you don't act on it. Am I clear?"

Midoriya nodded.

"Am I really?" he asked again. "Because I remember a few incidents where you decided to take matters into your own hands. Hosu and Kamino come to mind."

Midoriya at least had the decency to look embarrassed.

"Now, let me be clear," Aizawa continued, "in Hosu, you weren't given the option of leaving it to the pros, and in both cases, there was a positive outcome. That isn't possible here." He waited, watching his words sink in, and when Midoriya nodded his understanding, he continued. "UA has been made aware that there is a traitor somewhere in the school." Midoriya's eyes widened, but Aizawa pressed on before the boy could say anything. "As of yet, we don't know if they are a student or a teacher, but we cannot afford to tip our hand or start a witch hunt sowing distrust among our allies."

"I think I understand, sir," Midoriya said, taking advantage of the pause Aizawa had left. "Everyone knowing will only impede the investigation, but then why are you telling me?"

"Nedzu is convinced you're in the clear, for reasons I'm fairly certain I just found out," Aizawa answered, "and you need to know why I'm so concerned about the missing journal and the existence of the others."

Midoriya looked confused. "But, sir, if they're in UA, then they'll have a chance to make the same observations."

"And that brings us back to your self-deprecation."

"But-"

"No, listen, Midoriya."

His mouth shut with a click.

"You think that these," Aizawa gestures to the stack of books, "are only useful to you. Just the ramblings of an observant fanboy that bothered to write them down."

"Yes, that's exactly-" Midoriya stopped talking and hunched his shoulders slightly under Aizawa's glare.

"Have you ever heard of what some call the 10,000-hour rule?"

Midoriya glanced up and shook his head.

"It's the idea that it takes 10,000 hours of dedicated work to become world class at a given skill. Over the course of ten years, that's four hours a day." Midoriya looked particularly interested. "Mind you, hard work and determination can only take you so far, especially if you don't have any outside instruction. That's even more true with mental skills or ones that rely on muscle memory where you can fall into bad habits that will later have to be broken to make any progress. And I doubt you've been able to spend four hours every day over the past ten years, but you have been cultivating this since-" he sifted through the pile, pulling out the oldest (a small, brightly colored thing with All Might doodles on the front) "-since before you actually knew how to write." (The misspelling was also a giveaway.) "And you have only gained in time, encouragement, and constructive criticism since coming to UA, and you can test some of your theories now."

"You sound like they're anything impressive."

"You should take pride in your work."

Midoriya turned bright red and began sputtering out denials. Finally, he got his mouth under control. "But Kacchan can analyze quirks, and Uraraka found an even better strategy than I did for her match against Kacchan," he said, "and neither of them have been working on analysis like I have."

"Bakugou had a knack for understanding quirks, yes, and Uraraka understands her own limitations and the thoughts and behaviors of your classmates. You have all of that and then some," Aizawa said. Midoriya opened his mouth to argue, but Aizawa didn't let him. "When was the last time you were wrong about the outcome of a training exercise you weren't a part of? How often are you wrong about your classmates' strategies when you do participate?"

Midoriya looked sufficiently chastised.

"Both Uraraka and Bakugou need more time than you do to reach a similar place, and both focus on one aspect more than the other. You understand people- not just your classmates, _people_ \- and quirks. You can pick apart quirks and behaviors and develop strategies faster than any other first year excepting those with analysis quirks, and even they have blind spots with what their quirk won't tell them."

"You really think I'm that good?"

"Yes." Aizawa picked up number fourteen. "I recognized some of the videos you pulled from UA's servers. We usually use them for papers with this exact type of exercise. One in particular-" he flipped it open "-the bomb retrieval and defusal with Civilbots*. Four heroes failed to evacuate and defuse while three villains ran interference."

"I remember it." Midoriya had perked up a bit, curious.

"We use that for second years after they run that exercise for the first time. How long did you take on these notes?"

"Maybe two hours?" Midoriya looked thoughtful. "I had to do some research on bomb threats to make sure my strategies were viable."

The grin on Aizawa's face would be concerning to anyone that wasn't one of his kids. "We give them a week to go over the video and write up their report. If you formalized these notes-" he put the notebook down, still open and tapped at the pages "-it would get you a pretty good grade. There are mistakes, of course, but you're looking at it in only two hours, with limited information on the exercise, and a year ahead of when you normally would. Right now… maybe you'd get eighty-four percent. In a year, pouring your all into it with the relevant information… you'd do much better."

Midoriya blushed but grinned and didn't argue.

"Now, let's go back to the missing one."

Midoriya paled. Clearly, Aizawa had finally gotten through to him. "I didn't mention any names, and it's all in shorthand, so that'll slow them down, but it's not coded, so it won't stop them if a villain or the traitor got their hands on it. There's also only ten heroes in it so far."

Aizawa nodded. He'd noticed the shorthand in thirteen and fourteen. Midoriya seemed to use it when he was actively observing and wrote stream of consciousness style. When he was synthesizing and ruling out theories he'd write in plain Japanese. "Which heroes?"

Midoriya listed them off. Most were fairly small time and unlikely to attract much attention, but that also meant that if the villain could decipher Midoriya's notes and chose to use them, they likely wouldn't be able to do much. None of them were underground either (obviously, otherwise Midoriya wouldn't have seen them without going places he really shouldn't), so popularity would actually correlate to skill to some degree. Aizawa made a note to inform them of the breech later if the notebook wasn't found before he was finished with Midoriya.

"What now, sir?"

Aizawa must have gotten lost in thought. That didn't happen often. "Now, we burn these journals, and number fifteen if your classmates find it, and then we make sure you know how to encode your journals, so this won't be a concern in the future."

Midoriya nodded. "Won't encoding them make villains even more interested? Wouldn't it be safer for me to stop entirely?"

"Not if you want to keep developing this skill, and, given how useful it's going to be, you will keep developing it. As for your concerns about someone putting in the effort to crack the code, Nedzu has a habit of making up new codes for fun. They're essentially their own language- actually, no, they are their own language, and they draw from so many different sources and run counter to so many common perceptions that it's nearly impossible to crack without a key. They'd be better off smashing their head into a wall."

"He'd do that…" Midoriya was staring wide eyed. "He'd make one for me?"

Aizawa nodded. "He makes them for most underground heroes that go through UA, or pretty much anyone that asks and he thinks has actual need for one. I've even got one. They all are completely unique down to the writing system. I'll set up lessons for you with him as soon as it's ready. In the meantime, yes, you should stop writing."

"Yes, sir."

"Would you like to come with me when I burn them?"

"… I'd like that. Thank you, sir."

Aizawa nodded. "C'mon. Let's go check to see if your classmates found it before we get started."

Midoriya nodded and stood, beginning to collect his notebooks. Before he could get too far, Aizawa handed him a bag to carry them in, and they began their walk in silence. Aizawa let the air settle between them. Midoriya needed to process that he was going to actually be destroying his notes. Destroying something he had poured himself into for the vast majority of his life. This probably was his life. It was the closest thing he had to a physical representation of all he'd done, of what he'd achieved and where he'd started. And now he had to destroy it. Some of the earlier books might be safe to keep, but, in the end, saving them wouldn't likely mean much. Not without the context of the books to follow.

"Mr. Aizawa!"

Both Aizawa and his student stopped in the hall, looking up to see Uraraka walking towards them, a grin on her face and a slim notebook in her hands. By his side, Aizawa felt Midoriya sag in relief and mutter a quiet "Thank god."

"Uraraka," Aizawa greeted as she stopped in front of them, "is that the missing journal?"

She nodded and held out the notebook to Midoriya. "Here you go, Deku! We accidentally left it at the ice cream shop we stopped at before we came back."

Midoriya gave her a shaky smile and took the notebook from her, staring at it and slowly rubbing at the cover. "Thanks, Uraraka. You're a real life saver. Now, we just need to tell the others they can stop and… wrap things up." He pushed his thoughts aside with a slight shake of his head and put the notebook in the bag with the others.

"Iida's taking care of telling the rest of the class," Uraraka told them. She hesitated, not sure what she was supposed to do now.

"Midoriya and I have a few more things to take care of," Aizawa said, placing a hand on Midoriya's shoulder. "You can return to the dorms if you'd like."

She nodded, giving Midoriya one last smile. "I'll see you later then, Deku!"

"Yeah," Midoriya nodded. "See, you later."

Uraraka left quickly, still smiling. Aizawa and Midoriya both waited, watching until she disappeared around a corner. Midoriya's smile slowly fell, and Aizawa squeezed his shoulder, pulling him along.

Aizawa led them through the school, Midoriya falling silent again. Turn after turn, through the hallways, out a back door and towards some training grounds. As they approached, they came across Cementoss, who gave them a bundle of firewood and made a fire pit from the cement covering the ground in ground delta with a few buckets of water nearby. Aizawa thanked him while Midoriya wondered when he'd organized this. (Aizawa didn't. Nedzu did. Nedzu knows when something happens in UA, and Aizawa has learned to stop asking questions.) Cementoss left as soon as he was done.

The fire was large, and Aizawa sat back and watched once it was built, letting Midoriya handle the rest. Midoriya hesitated and watched each book burn, paging through the next before adding it to the flames. Tears run down his face. He wasn't sobbing with his body shaking and rushing rivers of tears as he gasped for breath like he normally does, just quietly crying and sniffling with a slow steady stream of tears dripping down as he mourns the destruction of his work. With the pace Midoriya set, Aizawa has to add a few logs to keep it going properly, but that is as much as he does.

When Midoriya is done, the sun has set, but he makes no move to get up, simply staring at the fire. Aizawa lets him. An hour passed, and the flames started to die. Embers glowing an ever shifting red and white that only barely lights up anything at all. Hazy outlines are all that they can really see.

Once again, Aizawa stepped forward and placed a hand on his student's shoulder. "It's time to go," he said. Midoriya nodded and stood, and they both pick up one of the buckets, pouring the water over the embers. The embers hiss and steam, the light suddenly dying.

Midoriya wiped his cheeks and eyes in the dark, taking deep breaths to try and stop the tears. He knows it won't work, but he tries anyway. Aizawa pulled out a flashlight and began the trip back, Midoriya's footsteps behind him the only sign that he's being followed.

Halfway back, Midoriya starts talking again. It isn't anything specific, just inane babbling to fill the air and fend off the quiet. Aizawa lets him, listening as his student describes Iida and Uraraka's little ticks, how Todoroki has made so much progress with his fire since the sports festival, how Bakugou ( _Kacchan_ ) and Sato are the only ones that really know how to cook, and funny little stories about all his classmates.

He also talks about how he was quirkless. Aizawa assumes Midoriya feels safe telling him that now that he knows about Midoriya's quirk and his relationship to All Might. He talks about the bullying and how he didn't have any friends and how the teachers didn't stop anything even if the other kids got violent in class, about how grateful he was when Aizawa showed he would. (Aizawa thinks those teachers deserve to have their licenses revoked and the school should have a complete overhaul if no one did anything, but he doesn't say anything. That's not what Midoriya needs right now.)

Somehow, Midoriya circles back to happier things by the time they make it back to the dorms, and Aizawa knows so much more than he thought he would. He bids his now smiling (though it's still strained) student goodnight at the doorstep and watches him go inside. The tears had long since dried up, and Aizawa knows Midoriya will be fine, even if he's still hurting. He'll recover. He's too strong not to.

* * *

 ***Okay, Civilbots are just little robots like the ones UA uses for security and to carry students to Recovery Girl, these ones are just programmed to function as civilians in the environment. I nicked the idea from the _Hero Class Villains_ series by RogueDruid (Icarius51) on AO3.**

 **Thank you all for reading, please don't forget to favorite, follow, or let me know what you think in the comments!**

 **NoS**


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